I ran over the grammatical errors and mistakes. Critiques and suggestions are recommended. I hope to publish this very soon once all of the mistakes are fixed and suggestions are formatted into the article. Thanks for helping!

Okay, taking a quick look at this since it fell to page 4 with no replies. Here we go, these are my thoughts:

"One of SCP-3XXX's instances, SCP-3XXX-1" > "instance of SCP-XXXX" is not the same as "SCP-XXXX-1". XXXX-1 is usually a sub-designation, denoting a specific part of the main anomaly that is usually distinct from it. This might be a quibble on my part, but I'm not sure if I've ever seen XXXX-1 being noted as the same as an XXXX.

"contained in an 8 x 8 x 8 meter chamber" > …why? 8 meters is about 26 feet, almost the height of a three story building. At that point it's more of a hangar than a chamber. Also, why a perfect cube? Is containment compromised if it's not a perfect cube? If not, no need to require the specifics.

Area 17 > hyphen please? Area-17.

"A steel railing 50 mm thick is placed around SCP-3XXX-1" > …why?

along with an elevator that descends from the top of SCP-3XXX-1's containment chamber to the bottom of SCP-3XXX > why an elevator? Wouldn't it be a huge pain to keep it powered?

Why did the Foundation decide they needed to put the chasm in a giant box? Also, how does that even work? Did they dig around the chasm to build extra underground walls around it?

All subjects who go past the railing > Don't refer to an individual as a "subject" unless you've established the experimental protocol they're being subjected to. If there's no research design or observation ongoing, they're not a subject of anything and shouldn't be called such.

must stand clear 1 m. > clear of what?

to reduce subject injuries and/or death. > if there's a chance of injury or death, why is a thin railing the only barrier to the chasm?

At that point I just got too incredulous to keep reading, and just skimmed the rest. In all honesty… it's kind of boring. We've gotten a lot of mysterious holes/chasms/caverns/ditches posted to the mainsite, most of them deleted because of predictability, since it's usually just "there's something in the hole that will hurt you, so we need to lock this up with a ton of unnecessary stuff".

The ones remaining typically have some sort of interesting twist to them besides "there's some random stuff inside the hole". SCP-1437 leads to other universes, which all have their own documentation of their versions of the hole. SCP-1322 presents a scenario that escalates into war through the hole. SCP-1162 presents a humorous exchange approach. And so on.

I can see that your critiques are mostly on the containment procedures than the description itself.

Yes, because by the time I finished reading the containment procedures, I didn't think it'd be worth it to critique the description in detail. That does not mean that the description is free of mistakes.

I'll change it if it needs to be.

It does need to be change. Please use the Ideas and Brainstorming forum.